Flexible monolayer elastomer films and bag for medical use

ABSTRACT

Soft, flexible films suitable for human skin contact are required for disposable medical devices. Soft, flexible monolayer elastomer films have been developed that are suitable for human skin contact and provide improved low-temperature flexibility and improved strength to weight ratio over conventional polyvinyl chloride films for medical uses. Embodiments of the flexible monolayer elastomer film comprise styrene-ethylene-propylene-styrene block copolymers (SEPS), SEPS/polyolefin mixtures, SEPS/polyolefin/ethylene-vinyl acetate (EVA) copolymer mixtures, and EVA/polyolefin mixtures

[0001] This application claims priority from U.S. ProvisionalApplication 60/265,324, filed Feb. 1, 2001; 60/265,325, filed Feb. 1,2001; 60/265,326, filed Feb. 1, 2001; 60/265,882, filed Feb. 5, 2001;and 60/265,883, filed Feb. 5, 2001; the entire disclosures of each ofwhich are herein incorporated by reference.

TECHNICAL FIELD

[0002] The present invention relates to the field of flexible monolayerelastomer films, and more particularly, to an improved elastomer filmfor medical uses, such as disposable medical devices.

BACKGROUND OF THE INVENTION

[0003] An important aim of ongoing research in the disposable medicaldevice industry is to provide soft, non-tacky packaging suitable forcontact with human skin without the use of plasticizers. A further aimof ongoing research is to provide flexible packaging for biological andpharmaceutical materials, which does not become brittle while undergoingliquid nitrogen storage.

[0004] Films used in the fabrication of disposable medical devicesrequire several specific attributes. Among the attributes are clarity,ability to seal using radio frequency (RF), flexibility, conformance toUnited States Pharmacopoeia (USP) Class VI and European Pharmacopoeia3^(rd) edition 3.1.6 test protocol, extremely low levels ofextractables, excellent barriers to water vapor transmission,permeability to gases, resistance to change during sterilization viaautoclaving, gamma radiation, or ethylene oxide, and, as required,compatibility with medical products contained in the disposable medicaldevice. In addition, it is desirable that the films have a soft,non-tacky texture because they will come in contact with human skin.

[0005] In certain applications, it is required that the disposablemedical devices be capable of prolonged storage in liquid nitrogen. Afilm that remains flexible and does not become brittle when stored inliquid nitrogen is required for storage of biological products, such asstem cells and bone marrow.

[0006] In addition, the film used for packaging medical products shouldhave extremely low levels of extractable and leachable materials toavoid contamination of the stored material. For example, anti-cancerpharmaceuticals, such as taxol, are particularly prone to contaminationby plasticizers, such as oils, leaching from conventional storage bags.In another example, extractable metals, such as aluminum, areunacceptable for peritoneal dialysis uses. Aluminum levels above about11 ppb exacerbate certain illnesses, including anemia andencephalopathy.

[0007] Polyvinyl chloride (PVC) films conform to a number of theserequirements and are conventionally used as a flexible medical productpackaging material. PVC provides a relatively inexpensive, clear, soft,and flexible film for medical products packaging. In addition, PVC isrelatively inert and contains low levels of extractable materials.However, to impart softness and flexibility to PVC films, plasticizersare added to PVC resins. The plasticizers are typically oils added inthe hundreds of ppm range. While the amount of oil is acceptable formany medical end uses, plasticizer tends to leach from the film. Theamount of plasticizer that leaches from the PVC film is unacceptable forstorage of certain pharmaceuticals, such as the anti-cancer drug taxol.

[0008] PVC formulations also require a heat stabilizer to prevent thePVC from undergoing heat degradation and color change during and afterprocessing. Heat stabilizers are extracted from the PVC by aqueoussolutions stored in the bag.

[0009] Another important characteristic of biological packaging is gaspermeability. Living cells, such as red blood cells and platelets, needto exchange oxygen and carbon dioxide. PVC gas permeability decreases asplasticizer levels decreases. Thus as the amount of plasticizer isincreased to provide high gas permeability in PVC based medical bags,the amount of plasticizer used and the amount of plasticizer thatleaches into the stored material also increases.

[0010] PVC is not suitable for liquid nitrogen storage of biologicalmaterials, such as stem cells or bone marrow. PVC becomes brittle whenstored in liquid nitrogen.

[0011] Various replacements for PVC film as a component of disposablemedical devices have been disclosed. U.S. Pat. No. 4,140,162 disclosesclear, blow-moldable medical packaging. However, the disclosedcomposition comprises an antioxidant material and Kraton G, astyrene-ethylene-butylene-styrene copolymer (SEBS). SEBS is tacky andrubbery and does not provide the soft PVC-like texture desired for humanskin contact.

[0012] U.S. Pat. No. 4,440,815 discloses a clear, flexible,thermoplastic medical liquid container comprising a mixture of SEBS,polypropylene, ethylene-lower alkyl acrylate polymer, and mineral oil.The mineral oil is added to improve clarity and flexibility. However,mineral oil is susceptible to leaching and subsequent contamination ofthe material stored in the medical liquid container.

[0013] U.S. Pat. No. 4,814,375 discloses a soft, high strengthelastomeric composition for use in medical and pharmaceutical productscomprising SEBS, a mineral oil plasticizer to soften the SEBS, and anacrylic resin.

[0014] U.S. Pat. No. 4,479,989 discloses a film material for use insterilized medical solution containers comprising linear low-densitypolyethylene (LLDPE) and SEBS.

[0015] U.S. Pat. No. 6,017,598 discloses a medical bag comprisingmultiple polymer film layers, wherein one of the layers comprises amatrix comprising a block copolymer, such as SEBS, and a polyolefin.

[0016] EP 0 740 544 B1 discloses a plastic formulation for a storagecontainer for blood components comprising an ethylene-vinyl acetatecopolymer (EVA), SEBS, and ultra-low density polyethylene (ULDPE).

[0017] The term “disposable medical devices” as used herein, is not tobe limited to the specifically disclosed embodiments. Disposable medicaldevices, as used herein, includes storage containers for medicalproducts, such as blood component bags, peritoneal dialysis sets,drainage collection bags, intravenous solution storage, and drugdelivery systems.

[0018] The term “medical products” as used herein, is not to be limitedto the specifically disclosed embodiments. Medical products, as usedherein, includes nutritional products; biological products, such as stemcells, blood components, and bone marrow; and pharmaceutical products,such as peritoneal dialysis solutions and drugs, such as taxol.

[0019] The term “essentially free of leachable material”, as usedherein, means there is either no leachable material in the flexiblemonolayer elastomer film or the amount of leachable material is so lowas to not adversely affect the medical products stored within disposablemedical devices formed from the flexible monolayer elastomer film. Noleachable materials, such as plasticizers, are added to the elastomerfilm material. The flexible monolayer elastomer films meet the EuropeanPharmacopoeia 3^(rd) edition 3.1.6 and USP Class VI test protocols.

[0020] The term “texture”, as used herein, means the tactile quality ofthe surface of the flexible monolayer elastomer film.

[0021] The term “the texture being substantially that of plasticizedpolyvinyl chloride”, as used herein, means that the texture of theflexible monolayer elastomer film is like that of plasticized polyvinylchloride films conventionally used in disposable medical devices, suchas the films in Comparative Examples 1-5 of the instant disclosure.

SUMMARY OF THE INVENTION

[0022] There exists a need in the disposable medical device art toprovide a medical product packaging material, which has a texture likethat of plasticized polyvinyl chloride and is free of any leachablematerial, such as plasticizer. There exists a need in this art toprovide medical product packaging material that can be stored in liquidnitrogen without becoming brittle. There exists a need in this art toprovide a medical product packaging material that can be sterilized byautoclaving, irradiation, or ethylene oxide. There exists a need in thisart to provide an economical medical product packaging material that isheat welded or radio frequency (RF) welded to form a flexible,monolayer, gas-permeable, elastomer bag for storing liquid medicalproducts.

[0023] These and other needs are met by embodiments of the presentinvention, which provide a flexible monolayer elastomer film comprisinga styrene-ethylene-propylene-styrene block copolymer. The film has atexture substantially that of plasticized polyvinyl chloride and thefilm is essentially free of leachable material.

[0024] The earlier stated needs are also met by certain embodiments ofthe instant invention which provide a flexible monolayer elastomer filmcomprising from about 55% to about 75% by weight of an ethylene-vinylacetate copolymer and from about 25% to about 45% by weight of ametallocene catalyzed ethylene-octene copolymer. The film has a texturesubstantially that of plasticized polyvinyl chloride and the film isessentially free of leachable material.

[0025] The earlier stated needs are further met by certain embodimentsof the instant invention including a flexible monolayer bag for storingmedical products, wherein the bag is RF welded from a flexible monolayerelastomer film comprising a styrene-ethylene-propylene-styrene blockcopolymer. The film has a texture substantially that of plasticizedpolyvinyl chloride and the film is essentially free of leachablematerial.

[0026] The earlier stated needs are further met by certain embodimentsof the instant invention including a flexible monolayer bag for storingmedical products, wherein the bag is formed from a flexible monolayerelastomer film comprising from about 55% to about 75% by weight of anethylene-vinyl acetate copolymer and from about 25% to about 45% byweight of a metallocene catalyzed ethylene-octene copolymer. The filmhas a texture substantially that of plasticized polyvinyl chloride andthe film is essentially free of leachable material.

BRIEF DESCRIPTION OF THE DRAWING

[0027]FIG. 1 is a plan view of a flexible monolayer blood component bagof the instant invention that is made from a flexible monolayerelastomer film of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention enables the production of disposablemedical devices with improved inertness towards medical products storedtherein, improved flexibility, improved gas permeability, and improvedlow temperature storage properties. The present invention provides softplasticized polyvinyl chloride-like texture without the use of leachableplasticizers and surfactants. The present invention further provides agas permeable disposable medical device which main remains flexible whenstored in liquid nitrogen. These benefits are provided by a flexiblemonolayer elastomer film comprising a styrene-ethylene-propylene-styreneblock copolymer (SEPS) that is essentially free of leachable materials.These benefits are also provided by a flexible monolayer elastomer filmthat is essentially free of leachable materials comprising anethylene-vinyl acetate copolymer (EVA) and a metallocene catalyzedethylene-octene copolymer.

[0029] The flexible monolayer elastomer film of the instant inventionhas a soft, flexible, dry feel similar to that of conventionalplasticized PVC medical films. The flexible monolayer elastomer film ofthe instant invention has suppleness similar to that of conventionalplasticized PVC medical films. The elastomer film of the instantinvention also has excellent clarity. Disposable medical devices areeasily fabricated from the film by radio frequency (RF) welding or heatwelding enabling its use on current device manufacturing equipment.Certain embodiments of the flexible monolayer elastomer film of theinstant invention can be sterilized by gamma radiation. There is minimalvisual or physical property changes when the elastomer film is exposedto high levels of gamma radiation. Other certain embodiments of theflexible monolayer elastomer film of the instant invention can besterilized by autoclaving. The film of the instant invention hasexcellent performance at low temperatures. Certain embodiments of thefilm of the instant invention remain flexible, and do not become brittlewhen stored in liquid nitrogen.

[0030] The absence of extractables exhibited by the flexible monolayerelastomer film of the instant invention makes it ideally suited for themost critical of device applications. No plasticizer or surfactants areadded to the film of the instant invention. Therefore, the flexiblemonolayer elastomer film of the instant invention is free or at leastessentially free of leachable materials, such as plasticizers. Inaddition, the film of the instant invention is resistant to most acidsand bases.

[0031] The flexible monolayer elastomer films of the instant inventionhave excellent strength to thickness ratios. The excellent strength tothickness ratio allows for significant down gauging. For example, anarticle fabricated from a 0.009″ thick film of the instant inventionwill exhibit the strength and durability equivalent to a 0.014″ thicksoft PVC film. The yield for a 0.009″×12″ films of the instant inventionis 7.8 yards per pound. For comparison, a typical 0.014″×12″ PVC filmhas a yield of only 4.0 yards per pound.

[0032] The unique combination of properties of the film of the instantinvention allows the film's use in applications such as intravenoussolution storage, drug delivery, nutritional solutions, storage of bloodcomponents, stem cell storage, bone marrow storage, peritoneal dialysis,and drainage collection as well as many other critical end uses.

[0033] Certain embodiments of the flexible monolayer elastomer film ofthe instant invention can be manufactured in thicknesses ranging from0.006″ to 0.020″ at widths up to 34″ and with surface finishes ofpolish/matte, taffeta/matte or matte/matte. Typical tolerance for thefilm thickness is +/−0.001″ and +/−0.125″ for the film width.

[0034] Certain embodiments of the flexible monolayer elastomer film ofthe instant invention are specially formulated to meet USP Class VI andEuropean Pharmacopoeia requirements.

[0035] In certain embodiments of the flexible monolayer elastomer filmof the instant invention, the film comprises SEPS. The film has atexture substantially that of plasticized polyvinyl chloride and thefilm is essentially free of leachable material. The film is essentiallyfree of plasticizers, such as oils, and surfactants. In embodiments ofthe instant invention containing SEPS, the amount of SEPS in the film isfrom about 5% to about 90% by weight of the film. In certainembodiments, the amount of SEPS in the film is from about 15% to about90% by weight of the film. In other certain embodiments the amount ofSEPS in the film is from about 15% to about 25% of the weight of thefilm. A suitable SEPS for certain embodiments of the present inventionis a medical grade SEPS, Hybrar® 7125, from Kuraray Co., Ltd.

[0036] The film of the instant invention can further comprise apolyolefin in an amount of about 5% to about 50% by weight of the film.In certain embodiments the amount of polyolefin is from about 14% toabout 30% by weight of the film. Among the polyolefins in certainembodiments of the instant invention are: a metallocene catalyzedpolyethylene-octene copolymer, a syndiotactic polypropylene, apolypropylene homopolymer, a polypropylene copolymer, a metallocenecatalyzed isotactic polypropylene, a low-density polyethylene, and alinear low-density polyethylene.

[0037] Suitable polyolefins for certain embodiments of the instantinvention include: Engage EG 8100 metallocene catalyzed saturatedethylene-octene extremely low density copolymer (VvLDPE) from DowPlastics, Tenite 800A low density polyethylene (LDPE) from EastmanChemical Company, EOD 96-30 and EOD 99-19 syndiotactic polypropylenesfrom Atofina Petrochemical, Inc., Dowlex 2045 linear low densitypolyethylene (LLDPE), Inspire H701-20NA polypropylene homopolymer andH707-12 polypropylene copolymer from Dow Plastics, 3727W Ziegler-Nattacatalyzed polypropylene homopolymer, EOD 00-11 metallocene catalyzedisotactic polypropylene and EOD 96-30 syndiotactic polypropylene fromAtofina Petrochemical, Inc.

[0038] The films of the instant invention can additionally comprise anethylene-vinyl acetate copolymer (EVA) in an amount of from about 40% toabout 90% by weight of the film. In certain embodiments, the amount ofethylene-vinyl acetate copolymer is from about 50% to about 65%. Incertain embodiments, the amount of vinyl acetate in the ethylene-vinylacetate copolymer is about 20% to about 28% by weight of theethylene-vinyl acetate copolymer. In certain embodiments, the amount ofvinyl acetate in the copolymer is about 28%.

[0039] Suitable ethylene-vinyl acetate copolymers for use in the filmsof the instant invention include Escorene Ultra LD 760 and EscoreneUltra LD 768 from ExxonMobil Chemicals, Ateva® 2803MG from AT Plastics,and Ultrathene® UE 634-000 from Equistar Chemicals.

[0040] The flexible monolayer elastomer films of the instant inventionhave high oxygen and carbon dioxide transmission rates and low watervapor transmission rates. The films of the instant invention containingSEPS have an oxygen transmission rate of from about 50 cm³/100 in²/24hours to about 300 cm³/100 in²/24 hours, a carbon dioxide transmissionrate of from about 300 cm³/100 in²/24 hours to about 2100 cm³/100 in²/24hours, and a water vapor transmission rate of from about 0.05 g/100in²/24 hours to about 1.25 g/100 in²/24 hours; for 0.006″ thick films.Certain embodiments of the film have an oxygen transmission rate of fromabout 140 cm³/100 in²/24 hours to about 250 cm³/100 in²/24 hours, acarbon dioxide transmission rate of from about 1050 cm³/100 in²/24 hoursto about 1800 cm³/100 in²/24 hours, and a water vapor transmission rateof from about 0.38 g/100 in²/24 hours to about 1.25 g/100 in²/24 hours;for 0.006″ thick films.

[0041] In embodiments of the instant invention where the film comprisesfrom about 55% to about 75% by weight of an ethylene-vinyl acetatecopolymer and from about 25% to about 45% by weight of an metallocenecatalyzed ethylene-octene copolymer the films, the film has an oxygentransmission rate of from about 100 cm³/100 in²/24 hours to about 600cm³/100 in²/24 hours, a carbon dioxide transmission rate of from about1000 cm³/100 in²/24 hours to about 5000 cm³/100 in²/24 hours, and awater vapor transmission rate of from about 1.7 g/100 in²/24 hours toabout 2.7 g/100 in²/24 hours; for 0.006″ thick films. Certainembodiments of the films of the instant invention containing EVA andmetallocene catalyzed ethylene-octene copolymer have an oxygentransmission rate of from about 300 cm³/100 in²/24 hours to about 400cm³/100 in²/24 hours and a carbon dioxide transmission rate of fromabout 2500 cm³/100 in²/24 hours to about 3500 cm³/100 in²/24 hours; for0.006″ thick films.

[0042] The flexible monolayer elastomer films of the instant inventionare formed by mixing the individual polymer components according to theweight fraction of each polymer component in the film. The ingredientsof the film may be tumble-blended in a ribbon blender and then heatedand fused into pellets. Films of the instant invention and articles areformed from the pellets by extrusion. Alternatively, articles can beformed from the pellets by molding.

COMPARATIVE EXAMPLES

[0043] Comparative Example 1 is EH-222 polyvinyl chloride film withtrioctyl trimellitate (TOTM) plasticizer from Solvay Draka. ComparativeExample 2 is EH-3125 polyvinyl chloride film with (TOTM) plasticizerfrom Solvay Draka. Comparative Example 3 is ES-3049 polyvinyl chloridefilm with tributyl citrate plasticizer from Solvay Draka. ES-3000polyvinyl chloride film is di(2-ethyl hexyl) phthalate from Solvay Drakais Comparative Example 4. Medipak 3250 polyvinyl chloride film fromSolvay Draka is Comparative Example 5. Comparative Example 6 is EVA-1800from Solvay Draka.

EXAMPLES

[0044] Example 1 is an extruded monolayer film formed from a mixture ofSEPS, EVA, syndiotactic polypropylene, and low-density polypropylene.The film consists of 50% by weight of an EVA containing about 28% byweight vinyl acetate, 20% by weight of Hybrar 7125F SEPS, 15% by weightAtofina Petrochemical EOD 96-30 syndiotactic polypropylene, and 15% byweight Engage 8100 metallocene catalyzed polyethylene-octene copolymer.

[0045] Example 2 is an extruded monolayer film formed from a mixture ofSEPS, EVA, and extremely low-density polypropylene. The film consists of50% by weight of an EVA containing about 28% by weight vinyl acetate,20% by weight of Hybrar 7125F SEPS, and 30% by weight Engage 8100metallocene catalyzed polyethylene-octene copolymer.

[0046] Example 3 is an extruded monolayer film formed from a mixture ofSEPS, EVA, and syndiotactic polypropylene. The film consists of 65% byweight of an EVA containing about 28% by weight vinyl acetate, 21% byweight of Hybrar 7125F SEPS, and 14% by weight Atofina Petrochemical EOD96-30 syndiotactic polypropylene.

[0047] Examples 1-3 have excellent clarity, with a light transmission of89% and have only minimal visual or physical property changes whenexposed to high levels of gamma radiation. Examples 1 and 2 haveexcellent low temperature properties and Example 2 has superior lowtemperature properties. Disposable medical devices are easily fabricatedfrom the films of Examples 1-3 by RF welding or heat sealing. TABLE IComparative Comparative Comparative Example 1 Example 2 Example 3Example 1 Example 2 Example 3 PHYSICAL PROPERTIES Process CalenderCalender Calender Extruder Extruder Extruder RF Weldability Yes Yes YesYes Yes Yes Thickness, mils. 15.0 15.0 15.0 6.0 9.0 6.0 Hardness, ShoreA 71 68 67 71 67 70 Specific Gravity 1.20 1.19 1.19 0.90 0.92 0.91Tensile Strength MD(TD), psi 2000(1800) 1800(1900) 2400(2400) 2580(2150)3000(2600) 2300(2400) Elongation MD(TD), % 300(300) 260(300) 330(330)620(720) 640(700) 600(790) Modulus MD(TD), Lbs./in. 1000(900) 1000(900)  1050(1050) 570(470) 440(380) 600(440) Tear MD(TD), Lbs./in.275(250) 220(220) 235(271) 239(261) 240(270) Low Temp. Brittleness ° C.−32 −34 −40 −75 −195 −70 GAS & WATER PROPERTIES: WVTR (gms/100in²/24Hrs.)@25° C.; 0.82 1.70 0.97 0.69 0.75 100% RH; 0.006″ thick O₂Transmission (cm³/100in²/24 Hrs.)@25° C.; 78 143 241 186 205  0% RH;0.006″ thick CO₂ Transmission (cm³/100in²/24 Hrs.)@25° C.; 412 1450 17701242 1551  0% RH; 0.006″ thick STERILIZATION: Gamma Resistance, ColorChange Minimal Minimal Minimal Minimal Minimal Minimal Steam, 121° C.Yes Yes Yes No No No BIOSAFETY CONFORMITY: NAmSA, ′01 NAmSA, ′01 NamSA,′01 Toxikon, ′01 Toxikon, ′01 Toxikon, ′01 European PharmacopoeiaProtocol Testing⁽*⁾ Conforms Conforms Conforms BiocompabilityTesting⁽**⁾ Pass Pass Pass Pass Pass Pass CHEMICAL PROPERTIES: ReducingSubstances 0.5 0.3 0.4 0.1 0.2 0.2 UV₂₂₀ 0.09 0.17 0.09 0.00 0.02 0.01pH 5.6 6.0 5.9 6.0 6.1 5.9 pH Shift 0.4 0.1 0.1 0.2 0.2 0.1 ExtractableAluminum, ppm 0.01 0.00 0.00 0.01 0.01 0.00 Extractable Calcium, ppm 0.00.3 0.5 0.2 0.3 0.1 Extractable Zinc, ppm 0.7 0.7 1.3 0.0 0.0 0.0

[0048] The various physical characteristics displayed in Tables I, II,and III are determined via the test methods listed below. PhysicalCharacteristic Test Method Durometer Hardness, Shore A ASTM D-2240Specific Gravity ASTM D-792 Tensile Strength, psi ASTM D-638 Elongationat Break, % ASTM D-638 Modulus at 100% Elong. psi ASTM D-638 TearResistance, lbf/in. ASTM D-1004 Low Temperature Brittleness, ° C. ASTMD-1790 WVTR (gms/100 in²/24 Hrs.)@ ASTM E-96-80 (25° C.; 100% RH);(0.006″ thick) Oxygen Transmission ASTM D-3985 (cm³/100 in²/24 Hrs.)@(25° C.; 0% RH); (0.006″ thick) Carbon Dioxide Trans. ASTM D-1434(cm³/100 in²/24 Hrs.)@ (25° C.; 0% RH); (0.006″ thick) EuropeanPharmacopoeia Tests Specification Reducing Substances, mg/20 ml  2.0max. UV at 220 nm, 0.20 max. pH 5.0 to 7.0 pH Shift  −1 to +1Extractable Aluminum, ppm   0 to 0.05 Extractable Calcium, ppm   0 to2.0 Extractable Zinc, ppm   0 to 2.0

[0049] Example 4 is an extruded monolayer film formed from a mixture ofSEPS and Ziegler-Natta catalyzed polypropylene. The film consists of 70%by weight of Hybrar 7125F SEPS, and 30% by weight Atofina Petrochemical3727W polypropylene. The film of example 4 provides excellent claritywith a light transmission of 90%. The film of Example 4 can be easilyfabricated by heat sealing and can be sterilized by gamma irradiation,ethylene oxide, or autoclaving at 121° C. In addition, the film ofExample 4, has extremely low levels of extractable metals. TABLE IIComparative Comparative Example 4 Example 5 Example 4 PHYSICALPROPERTIES: Process Calender Extruder Extruder RF Weldablity Yes Yes NoThickness, mils 15.0 14.0 10.0 Hardness, Shore A 75 80 70 SpecificGravity 1.23 1.24 0.91 Tensile Strength MD(TD), psi 2800(2600)3600(3500) 2545(2771) Elongation MD(TD), % 280(300) 340(390) 752(821)Modulus MD(TD), psi 1250(1050) 1700(160O) 453(449) Tear MD(TD), Lbs./in.300(300) 550(520) 234(248) Low Temp. Brittleness ° C. −29 −26 −15 GAS &WATER PROPERTIES: WVTR (gms/100 in²/24 Hrs.) 0.53 0.32 0.09 25° C.; 100%RH; 0.006″ thick O₂ Transmission 44 28 68 (cm³/100 in²/24 Hrs.) 25° C.;0% RH; 0.006″ thick CO₂ Transmission 299 183 328 (cm³/100 in²/24 Hrs.)25° C.; 0% RH; 0.006″ thick STERILIZATION: Gamma Resistance, ColorChange Minimal Moderate Slight Steam, 121° C. Yes yes Yes BIOSAFETYCONFORMITY NAmSA, '01 Toxikon, 100 Toxikon, '01 European PharmacopoeiaProtocol Testing(*) Conforms Bicompatibility Testing(**) Pass pass PassCHEMICAL PROPERTIES: Reducing Substances 0.3 1.0 0.2 UV₂₂₀ 0.09 0.120.01 pH 5.6 5.5 5.9 pH Shift 0.4 −0.2 0.0 Extractable Aluminum, ppm 0.010.00 0.00 Extractable Calcium, ppm 0.2 0.4 0.1 Extractable Zinc, ppm 0.61.0 0.0

[0050] Example 5 is an extruded monolayer film formed from a mixture ofEVA and extremely low density polyethylene. The film consists of 65% byweight of an EVA containing about 28% by weight vinyl acetate, and 35%by weight Engage 8100 metallocene catalyzed polyethylene-octenecopolymer. Example 5 provides superior low temperature properties, andexcellent clarity with a light transmission of 91%. The film of Example5 can be easily fabricated by RF welding or heat sealing. Extremely highoxygen and carbon dioxide transmission is provided by the film ofExample 5. In addition, the film of Example 5, has extremely low levelsof extractable metals.

[0051] The Exemplary films and the Comparative Examples underwent invitro and in vivo testing by independent labs, such as NAmSA and Toxikonto demonstrate compliance with biomedical safety standards. Thefollowing tests, in accordance with USP and European ISO 10993 protocolswere performed:

[0052] ISO Intracutaneous Reactivity, Part 10

[0053] ISO Systemic Toxicity, Part 11

[0054] ISO Muscle Implantation with Hystopathology, Part 6

[0055] ISO Hemolysis in Vitro, Part 4

[0056] ISO Cytotoxicity (MEM Extraction), Part 5.

[0057] USP Physico-Chemical Tests

[0058] USP LAL Endotoxin Test in Vitro.

[0059] The films of Examples 1-5 passed all of the above-listedbiomedical safety standards. TABLE III Comparative Comparative Example 4Example 5 Example 4 PHYSICAL PROPERTIES: Process Calender ExtruderExtruder RF Weldability Yes Yes Yes Thickness, mils. 15.0 14.0 6.0Hardness, Shore A 75 90 70 Specific Gravity 1.23 0.939 0.92 TensileStrength MD(TD), psi 2800(2600) 2550(2500) 3000(2800) Elongation MD(TD),% 280(300) 400(700) 600(700) Modulus MD(TD), Lbs./in. 1250(1050)980(860) 630(480) Tear MD(TD), Lbs./in. 300(300) 4(5) 280(280) Low Temp.Brittleness ° C. −29 −59 −195 GAS & WATER PROPERTIES: WVTR (gms/100in²/24 Hrs.) @25° C.; 100% RH; 0.006″ thick 0.53 0.30 2.2 O₂Transmission 44 73 359 (cm³/100 in²/24 Hrs.) @25° C.; 0% RH; 0.006″thick CO₂ Transmission 299 386 2,954 (cm³/100 in²/24 Hrs.) @25° C.; 0%RH; 0.006″ thick STERILIZATION: Gamma Resistance, Color Change MinimalMinimal Slight Steam, 121° C. Yes No No BIOSAFETY CONFORMITY: NAmSA, '01NAmSA, '97 Toxikon, '01 European Pharmacopoeia Protocol Testing(*)Conforms Biocompability Testing(**) Pass Pass Pass CHEMICAL PROPERTIES:Reducing Substances 0.3 0.1 0.3 UV₂₂₀ 0.09 0.04 0.02 pH 5.6 4.7 6.0 pHShift 0.4 −1.0 0.1 Extractable Aluminum, ppm 0.01 0.00 0.00 ExtractableCalcium, ppm 0.2 0.0 0.1 Extractable Zinc, ppm 0.6 0.0 0.0

[0060] Other embodiments of the flexible monolayer elastomer film of theinstant invention include a film consisting of 60% by weight of an EVAcontaining about 28% by weight vinyl acetate, 20% by weight of Hybrar7125F SEPS, and 20% by weight of Tenite 800A LDPE. Another embodimentconsists of 60% by weight of an EVA containing about 28% by weight vinylacetate, 20% by weight of Hybrar 7125F SEPS, and 20% by weight ofAtofina Petrochemical EOD 99-19 syndiotactic polypropylene. Otherembodiments consist of 50% by weight of an EVA containing about 28% byweight vinyl acetate, 20% by weight of Hybrar 7125F SEPS, and 15% byweight of Atofina Petrochemical EOD 65-30 syndiotactic polypropylene,and 15% by weight of Dowlex 2045 LLDPE; 70% by weight of Hybrar 7125FSEPS and 30% by weight of Dow Inspire H701-20NA polypropylene or H707-12polypropylene copolymer; 80% by weight of Hybrar 7125F SEPS and 20% byweight Dow Inspire H701-20NA polypropylene or H707-12 polypropylenecopolymer; and 85% by weight of Hybrar 7125F SEPS and 15% by weightAtofina Petrochemical 3727W Ziegler-Natta catalyzed polypropylene or EOD00-11 metallocene catalyzed isotactic polypropylene.

[0061]FIG. 1 embodies one aspect of the instant invention. Disposablemedical devices, such as the blood component bag 10 of FIG. 1 are formedby heat sealing or RF welding monolayer films of the instant invention.Blood component bag 10 comprises a connector 12 connected to a length offlexible tubing 14, through which the blood components are introducedinto the blood component bag 10. The tubing 14 may contain a phlebotomyneedle (not shown) at its terminal end or may be connected to anothercontainer (not shown). The blood component bag 10 additionally comprisesone or more sealable access ports 16. The connector 12, flexible tubing14, access ports 16, and bag walls 18 are all made from the flexiblemonolayer elastomer film of the instant invention.

[0062] The flexible bag 10 of the instant invention is formed by RFwelding or heat sealing the monolayer elastomer walls 18 of the bag 10along the edges 20. Certain embodiments of the flexible bag 10 can bestored in liquid nitrogen without becoming brittle. Other embodiments ofblood component bag 10 have excellent high temperature properties andcan be sterilized by autoclaving at a temperature of about 121° C. orhigher. Alternatively, the flexible bag 10 can be sterilized by gammaradiation or ethylene oxide.

[0063] The embodiments described in the instant disclosure are forillustrative purposes only. They should not be construed to limit thescope of the claims. As is clear to one of ordinary skill in the art,the instant disclosure encompasses a wide variety of embodiments notspecifically described herein.

What is claimed is:
 1. A flexible monolayer elastomer film comprising astyrene-ethylene-propylene-styrene block copolymer, the film having atexture, the texture being substantially that of plasticized polyvinylchloride, and wherein the film is essentially free of leachablematerial.
 2. The flexible monolayer elastomer film of claim 1, whereinthe amount of styrene-ethylene-propylene-styrene block copolymer in saidfilm is from about 5% to about 90% by weight of the film.
 3. Theflexible monolayer elastomer film of claim 1, further comprising apolyolefin.
 4. The flexible monolayer elastomer film of claim 3, whereinthe polyolefin is selected from the group consisting of a metallocenecatalyzed polyethylene-octene copolymer, a syndiotactic polypropylene,an isotactic polypropylene, a polypropylene copolymer, a low-densitypolyethylene, and a linear low-density polyethylene, and the amount ofpolyolefin in said film is from about 5% to about 50% by weight of thefilm.
 5. The flexible monolayer elastomer film of claim 1, furthercomprising an ethylene-vinyl acetate copolymer.
 6. The flexiblemonolayer elastomer film of claim 5, wherein the amount ofethylene-vinyl acetate copolymer in the film is from about 40% to about90% by weight of the film.
 7. A flexible monolayer elastomer filmcomprising from about 55% to about 75% by weight of an ethylene-vinylacetate copolymer and from about 25% to about 45% by weight of ametallocene catalyzed ethylene-octene copolymer, the film having atexture, the texture being substantially that of plasticized polyvinylchloride, and wherein the film is essentially free of leachablematerial.
 8. A flexible monolayer bag for storing medical products,wherein the bag is RF welded from the flexible monolayer elastomer filmof claim
 1. 9. A flexible monolayer bag for storing medical products,wherein the bag is formed from the flexible monolayer elastomer film ofclaim
 3. 10. A flexible monolayer bag for storing medical products,wherein the bag is formed from the flexible monolayer elastomer film ofclaim 7.